The Clinical core will provide patient materials and epidemiologic information to each of the sub-projects as needed to complete their interactions. The core patient group will consist of women identified as recent contacts to men with chlamydial or gonococcal infection. Most (but not all) of the women will be infected. The study design ensures that most of the women have had only a single contact (to maintain the link in transmission) and, based on preliminary evidence, most will be infected.